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author | Derrick Stolee <dstolee@microsoft.com> | 2019-06-18 18:14:24 (GMT) |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2019-06-20 03:46:25 (GMT) |
commit | d4f4d60f6da8b93f768b2b4958c04cc1b3cea443 (patch) | |
tree | 1f88453dc1b3ff7d3e126b2288c9ae7076b360e3 /commit-graph.c | |
parent | 890345ac106f78dfcfcde002de39ebbb410e0b39 (diff) | |
download | git-d4f4d60f6da8b93f768b2b4958c04cc1b3cea443.zip git-d4f4d60f6da8b93f768b2b4958c04cc1b3cea443.tar.gz git-d4f4d60f6da8b93f768b2b4958c04cc1b3cea443.tar.bz2 |
commit-graph: prepare for commit-graph chains
To prepare for a chain of commit-graph files, augment the
commit_graph struct to point to a base commit_graph. As we load
commits from the graph, we may actually want to read from a base
file according to the graph position.
The "graph position" of a commit is given by concatenating the
lexicographic commit orders from each of the commit-graph files in
the chain. This means that we must distinguish two values:
* lexicographic index : the position within the lexicographic
order in a single commit-graph file.
* graph position: the position within the concatenated order
of multiple commit-graph files
Given the lexicographic index of a commit in a graph, we can
compute the graph position by adding the number of commits in
the lower-level graphs. To find the lexicographic index of
a commit, we subtract the number of commits in lower-level graphs.
While here, change insert_parent_or_die() to take a uint32_t
position, as that is the type used by its only caller and that
makes more sense with the limits in the commit-graph format.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'commit-graph.c')
-rw-r--r-- | commit-graph.c | 89 |
1 files changed, 78 insertions, 11 deletions
diff --git a/commit-graph.c b/commit-graph.c index 76d189d..8f5c093 100644 --- a/commit-graph.c +++ b/commit-graph.c @@ -359,9 +359,18 @@ int generation_numbers_enabled(struct repository *r) return !!first_generation; } +static void close_commit_graph_one(struct commit_graph *g) +{ + if (!g) + return; + + close_commit_graph_one(g->base_graph); + free_commit_graph(g); +} + void close_commit_graph(struct raw_object_store *o) { - free_commit_graph(o->commit_graph); + close_commit_graph_one(o->commit_graph); o->commit_graph = NULL; } @@ -371,18 +380,38 @@ static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t g->chunk_oid_lookup, g->hash_len, pos); } +static void load_oid_from_graph(struct commit_graph *g, + uint32_t pos, + struct object_id *oid) +{ + uint32_t lex_index; + + while (g && pos < g->num_commits_in_base) + g = g->base_graph; + + if (!g) + BUG("NULL commit-graph"); + + if (pos >= g->num_commits + g->num_commits_in_base) + die(_("invalid commit position. commit-graph is likely corrupt")); + + lex_index = pos - g->num_commits_in_base; + + hashcpy(oid->hash, g->chunk_oid_lookup + g->hash_len * lex_index); +} + static struct commit_list **insert_parent_or_die(struct repository *r, struct commit_graph *g, - uint64_t pos, + uint32_t pos, struct commit_list **pptr) { struct commit *c; struct object_id oid; - if (pos >= g->num_commits) - die("invalid parent position %"PRIu64, pos); + if (pos >= g->num_commits + g->num_commits_in_base) + die("invalid parent position %"PRIu32, pos); - hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos); + load_oid_from_graph(g, pos, &oid); c = lookup_commit(r, &oid); if (!c) die(_("could not find commit %s"), oid_to_hex(&oid)); @@ -392,7 +421,14 @@ static struct commit_list **insert_parent_or_die(struct repository *r, static void fill_commit_graph_info(struct commit *item, struct commit_graph *g, uint32_t pos) { - const unsigned char *commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * pos; + const unsigned char *commit_data; + uint32_t lex_index; + + while (pos < g->num_commits_in_base) + g = g->base_graph; + + lex_index = pos - g->num_commits_in_base; + commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * lex_index; item->graph_pos = pos; item->generation = get_be32(commit_data + g->hash_len + 8) >> 2; } @@ -405,10 +441,25 @@ static int fill_commit_in_graph(struct repository *r, uint32_t *parent_data_ptr; uint64_t date_low, date_high; struct commit_list **pptr; - const unsigned char *commit_data = g->chunk_commit_data + (g->hash_len + 16) * pos; + const unsigned char *commit_data; + uint32_t lex_index; - item->object.parsed = 1; + while (pos < g->num_commits_in_base) + g = g->base_graph; + + if (pos >= g->num_commits + g->num_commits_in_base) + die(_("invalid commit position. commit-graph is likely corrupt")); + + /* + * Store the "full" position, but then use the + * "local" position for the rest of the calculation. + */ item->graph_pos = pos; + lex_index = pos - g->num_commits_in_base; + + commit_data = g->chunk_commit_data + (g->hash_len + 16) * lex_index; + + item->object.parsed = 1; item->maybe_tree = NULL; @@ -452,7 +503,18 @@ static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uin *pos = item->graph_pos; return 1; } else { - return bsearch_graph(g, &(item->object.oid), pos); + struct commit_graph *cur_g = g; + uint32_t lex_index; + + while (cur_g && !bsearch_graph(cur_g, &(item->object.oid), &lex_index)) + cur_g = cur_g->base_graph; + + if (cur_g) { + *pos = lex_index + cur_g->num_commits_in_base; + return 1; + } + + return 0; } } @@ -492,8 +554,13 @@ static struct tree *load_tree_for_commit(struct repository *r, struct commit *c) { struct object_id oid; - const unsigned char *commit_data = g->chunk_commit_data + - GRAPH_DATA_WIDTH * (c->graph_pos); + const unsigned char *commit_data; + + while (c->graph_pos < g->num_commits_in_base) + g = g->base_graph; + + commit_data = g->chunk_commit_data + + GRAPH_DATA_WIDTH * (c->graph_pos - g->num_commits_in_base); hashcpy(oid.hash, commit_data); c->maybe_tree = lookup_tree(r, &oid); |